On Monday, July 30, 2018 at 5:13:07 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:30:23 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 2:37:58 PM UTC-4, wrote:

One more time S L O W L Y

I have a transformer with two 120v secondaries. Assume the taps are A
& B on each.
If they are wound around the core in the same direction from A to B,
do you agree each would be in phase if they are measured A to B.
Now if I connect them in series A to B do you agree the current is
going in the same direction in both windings so they are still in
phase? You will see 240v from the A to B on each end.
If they were connected A to A in series they would be 180 degrees out
of phase the voltage would be zero.
In fact they have to be in phase to add. Otherwise they buck.

Now look at your pole pig outside your house and tell me which one it
most closely resembles.

You are confusing the halves of one sine wave with two sine waves.
I don't know what the professor has to rationalize to teach this
simple thing to the snowflakes in his class.

Go ahead, keep disparaging the professor of electrical engineering
with 40 years of experience, who presented the paper I cited at
a power industry conference to his peers. I'm sure they are all
dumb snowflakes. Did you look at the math, where he did the analysis?
This coming from the guy who still can't give a definition of what
N phase power even means. I gave you two or three days, then I gave
you the simple definition that cover it all. One that doesn't rely
on transformers, generators, it's a complete, general definition.


You're hung up on transformers, components when it doesn't matter
how what's delivered over those 3 wires originates. As I've said many
times now, it could be from a center tapped transformer, a generator
with two windings sharing a neutral, or a black box with electronics
that synthesizes it electronically.



N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

Where is your definition? How can you argue about what something is or
isn't when you can't give the definition?

And again I note that neither you nor your new sidekick will answer
the simple two problems I laid out, ones that any beginning elect
engineer who took his first course in circuits could easily answer.
Here they are again. I can keep posting them at least as long as you
can refuse to answer:


Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?

So I run that into a house as 240/120, how many phases now?

If phase is so simple and you understand it, why can't you answer those
questions?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there.


As I said before, from an engineering perspective,
let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what power source
it uses? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?



Here;s another way of looking at it. Let's say you're an engineering student.
I put you in a house with 240/120 service, give you whatever instruments
and test gear you want, tell you to analyze the 3 wire service. You
don't know where it's coming from, how it's generated. Describe it and
how you would model it.

I can give you my answer. You have two 120V 60 hz sinusoidal voltage
sources that are 180 deg out of phase with each other that share a
common neutral. And that's how you'd model it, you need TWO ideal
voltage sources that are 180 deg out of phase with each other.
Or of opposite polarity if you like, which is exactly the same thing.
Note that I didn't need to reference transformers, synthesizers,
generators, or how many phases came from the power company. It's
completely defined by the electrons coming and going on those 3 wires,
without regard to how or where they were generated.